It has been estimated that roughly 3 billion discarded tires from autombiles and trucks litter the American landscape, and 200 million more are discarded every year. Although some discarded tires are dumped offshore to create fishing reefs, that method of disposal is impractical for tires located long distances from coastlines. Most discarded tires sit in open dumps, where they collect rainwater and serve as breeding grounds for mosquitos, rats, and other pests. More information on various problems relating to the disposal or recycling of discarded tires is contained in the introductory section of U.S. Pat. No. 4,726,530 (Miller and Priscu 1988).
Various machines have been developed to cut, grind, or shred discarded tires into fragments. Such machines are disclosed in, e.g., U.S. Pat. Nos. 3,561,308 (Ehrlich 1971), 4,405,090 (Wakeem 1983), 4,422,581 (Chryst 1983), and 4,757,949 (Horton 1988).
More elaborate systems that can remove strands or pieces of steel, fiberglass, polyester, nylon, or other materials used in the reinforcing belts, so that the remaining purified rubber fragments can be chemically processed, are described in various other patents such as U.S. Pat. No. 4,726,530 (Miller and Priscu 1988) and U.S. Pat. No. 4,813,614 (Moore and Aten 1989). However, such additional processing tends to be relatively expensive.
Despite the availability of machinery for cutting, grinding, or shredding tires into fragments of any desired size, the fact remains that millions of discarded tires continue to pile up in open dumps, where they become eyesores and breeding grounds for pests. Prior to this invention, not enough practical and economical uses have been available for rubber fragments from discarded tires.
One object of the subject invention is to provide a use for rubber fragments obtained by cutting, shredding, or grinding discarded tires.
Another object of the invention is to provide a use for discarded tires which can utilize fragments of rubber without requiring expensive processing to remove strands of steel, fiberglass, polyester, nylon, or other reinforcing material from the rubber.
A third object of the subject invention is to provide a method of recycling discarded tires into products that will substitute for lumber in certain settings, thereby reducing the number of trees that must be cut down in order to provide products that people need.
A fourth object of this invention is to provide articles which people need, which are made from recycled waste products that have no other practical and economic market rather than from virgin timber or other resources which are in demand and whose depletion imposes a serious cost on the environment.